212161620021 has 8 divisors (see below), whose sum is σ = 304642326240. Its totient is φ = 130560996912.

The previous prime is 212161619993. The next prime is 212161620031. The reversal of 212161620021 is 120026161212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 212161620021 - 2¹⁰ = 212161618997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212161619973 and 212161620000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212161620031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2720020731 + ... + 2720020808.

It is an arithmetic number, because the mean of its divisors is an integer number (38080290780).

Almost surely, 2^212161620021 is an apocalyptic number.

It is an amenable number.

212161620021 is a deficient number, since it is larger than the sum of its proper divisors (92480706219).

212161620021 is a wasteful number, since it uses less digits than its factorization.

212161620021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5440041555.

The product of its (nonzero) digits is 576, while the sum is 24.

Adding to 212161620021 its reverse (120026161212), we get a palindrome (332187781233).

The spelling of 212161620021 in words is "two hundred twelve billion, one hundred sixty-one million, six hundred twenty thousand, twenty-one".